Circuit wiring for windshields and the like



May 13, 1930. J. A. 'JOHNSON 1,758,704

` CIRCUIT WIRING FOR WINDSHIELDS AND THE.' LIKE Filed Aug. 5J 1929 Z3INVENTOR J CK AJ'oH/vso/V 7 9 BY ATTORNEY Patented May 13, 1930 UNI-TEDISTATES JACK A.. JOHNSON, 0F ROBBINSDALE, MINNESOTA PATENT OFFICEApplication led August 5, 1929. Serial No. 383,498.

This invention relates to means for heating glass panes, such as usedfor vehicle windshields, windows, and the like, to prevent theaccumulation thereon of ice, frost and condensation, and the primaryobject is to provide an improved means and method for wiring such glasswhereby the glass w1ll be heated, by high resistance wires imbeddedtherein when suitably connected in controlled circuit with a source ofelectricity. The in vention herein disclosed is particularly an.improvement over the structure illustrated in my cospendingapplication, Ser. No. 336,- 215, filed January 30, 1929, for windshield.

In the accompanying drawing, forming a part of this speciiication:

Fig. 1 is a plan elevation showing asheet of glass, in which my wiringsystem has been imbedded, the dotted cross lines indicating the methodof cutting the glass into sections for use as Windshields or windows.

Fig. 2 is an enlarged detail perspective view of one corner of a windowor windshield embodying the invention.

Fig. 3 is a sectional detail view on the line 3-3 in Fig. 2. v

Referring to thefdrawing more particularly and by reference characters,4f designates a sheet of glass, which may of course be of any size, andmay be measured .into as many sections as may be desired, depending uponthe size and number of finished sections to be cut. In the presentinstance` it is assumed 3f that the glass is of such a size as to formfour sections, A, B, C, and D, which are to be separated by cutting onthe` crossed lines 5 and 6, and after being cut will be y of a propersize for use as windshields or windows.

When making the glass sheet or 'plate 4 a number of spaced parallelwires 7 are imbedded in it and extend throughout the horizontal lengthof the glass. Before the wires are so placed or imbedded in the glassthey are provided at their ends with lugs or terminals 8, and midwaybetween their ends the wires are provided with similar lugs 9, whichyare longer than 8, however, so that when the glass is cut on the line5. the lugs at the ends of each section or panel A-D will be of equallength.

The wiresl 7 are' high-.resistance.wires,', which, when energized, willdevelopconsider-` able heat, to raise the temperature of the glass andthus prevent the accumulation of frost or other condensation, and asthese wires are imbedded in the body of the glass proper they will ofcourse be protected from atmospheric contact.

The lugs 8 and 9 are preferably of harder metal than the heating wiresfor which theyl serve as terminals, and can best `be secured thereto bybeing formed with axial holes to receive vthe wires, after which theymay .5 be spot welded or pinched, at their ends, upon the wires, to holdthem in place before being set in the glass. The exposed ends of thelugs are. then drilled and tapped to receive binding screws 10, as shownin Figs. 2 7 and 3, which in turn secure the electric circuit wires 11,that are to furnish the heat. ing current. Such current or circuit wiresmay be otherwise arranged and controlled in any suitable manner,although the plan described in my above noted application is desirable.'

The terminal members 9 and 10, as well as the circuit wires 11, arepreferably 'protected by a semi-tubular insulation 12, and 13 desigonates the frame of the windshield or window.

The novelty of the invention will no doubt be obvious from the foregoingdescription. It may be stated, however, that the greatest diilicultyencountered in setting up an arrangement wherein the inset wires have nolugs such as 8 and 9, is that when the glass is cut the wire is cut offHush with it, and therefore cannot be secured to an appropriateterminal, for connection with the circuit wires. This difficulty isentirely overcome in the present inst-ance, and there is also the addedadvantage that the heating element wires are not exposed to atmosphericcontact, even at their ends.

It is understood that suitable modifications may be made in thestructure as disclosed, provided such modifications come within thespirit and scope of the appended claims. Having now therefore fullyillustrated and 10 described my invention what ll claim to loe new enddesire to protect by Letters Patent is:

2l. A windshield or the like comprising a, glass piste, lugs imbedded inopposite edges of the glass, high resistance wires extending through theglass to eireuitously connect certain of the lugs, and binding screwsthreaded in the lugs to form terminals therewith Jfor I 'the wires 2.The method of circuit wiring a glass plate comprising the securing ofterminal lugs to the wires of the circuit, and then imbedding the wiresand lugs in the glass, while in a molten state.

3. The method of circuit wiring at glass yplate comprising the securingof terminal lugs to the wires of the circuit, and then imbedding thewires and lugs in the glass, While in a molten state, leaving the lugsexposed at one ,edge of the glass.

4. The method of circuit wiring a glass plate comprising the securing ofterminal lugs to the Wires of the circuit, and then im- `beddingtherwires and lugs in the glass, while in a. molten state, leaving thelugs exposed at one edge of the glass, and thereupon drilling andtapping the lugs for the engagement of binding screws.

Signed at' Minneapolis, in the county of Hennepin, and State ofMinnesota, this 3rd day of August, 1929.

JACK A. JOHNSON.

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